sel/all cameras preview generation

this script create previews (avi's) for selected and or all scene cameras and puts them in current project previews folder.

i created this, when i was reviewing few ppl work and each one has almost 10 cameras in max file. file was heavy enough to not show real time playback.

 it takes animation range from camera keys or time line (optional). camera animation only consider PRS or path keyframes. later on i'll add all other attributes if needed

todo's:

i was unable to manage codecs with maxscript, if someone knows, please reply with comments.

right now files created with this script are uncompressed avi's or bmp's, hopefully will have options in future

also right now it uses viewport resolution, you can change layout and then use a smaller viewport size